Boat trailer device

ABSTRACT

The present invention relates to a device at a trailer, especially a boat trailer, which includes a chassis supported by wheels and a coupling device in the front for connecting the trailer to a towing vehicle. A two-armed lever consists of arms which form an angle with each other and is pivoted in an axis of rotation which is oriented transversely at the back of the trailer. The first arm of the lever, which mainly points forward from the axis of rotation has a length that exceeds or falls below the length of the other arm of the lever. The two lever-arms comprise parallel arm elements, whose ends are connected to the ends of the axis of rotation and which at their outer ends are lined by transversal beams. A winch tower with a winch is provided at the front end of the trailer. The wire of the winch is adapted to run over the outer ends of the lever-arms and in its end is provided with lifting devices for the objects.

BACKGROUND OF THE INVENTION

The present invention relates to a trailer device including a chassissupported by wheels, a coupling device in the front of the trailer forconnecting the trailer to a towing vehicle, and a winch to facilitatemovement of an object along the trailer. In particular the inventionrelates to the trailer utilized as a lifting device for a boat.

When loading and unloading a trailer, in most cases it is necessary tomove heavy objects vertically as well as horizontally to and from thetrailer. If the object is heavy, access to a lifting device orassistance from other persons is usually required to perform thevertical movement. This leads to essential limitations with respect tothe usefulness of the trailer.

At launching and loading of pleasure-boats it is common practice to makeuse of a special boat trailer and a slanted ramp by means of which thetrailer can be driven down into and out of the water. As a result ofthis procedure the most sensitive components on the boat trailer arelowered into the water, possibly causing corrosion damage. Furthermore,at least two persons are usually necessary. When launching and loading aboat utilizing the prior art boat trailer and a ramp. One person isusually necessary to handle the towing vehicle and the boat trailer andanother person is necessary in the boat.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a trailer device whicheliminates said inconveniences and which can be operated by one person;particularly launching and loading of a boat from a quay, a pier or thelike. In accordance with the invention, this aim is obtained in that thedevice comprises a lever having a first and second arm, whose arms forman angle with respect to each other and are pivoted at an axis ofrotation which is oriented transversally at the back of the trailer. Thefirst arm of the lever, which mainly points forward from the axis ofrotation. has a length that exceeds or falls below the length of theother arm of the lever. Parallel arm elements comprise the first andsecond arms whose ends are connected to the ends of the axis of rotationand which at their outer ends are linked by transversal beams, at whichthe distance between the outer ends of the first arm exceeds or fallsbelow the distance between the outer ends of the second arm and limitsthe width of the objects that can be loaded onto or off of the trailer.A winch tower with a winch is provided at the front end of the trailer,whereby the wire of the winch is adapted to run over the outer ends ofthe first and second arms and at one end is provided with lifting meansfor the object. The device also includes means adapted to prevent motionbetween the first and second arms and the wire during predeterminedstages of the loading or unloading of the object.

To prevent motion during the predetermined stages of loading orunloading of the object, the transversal beam is provided with a blockthrough which the wire runs, which locks the wire in one direction andallows it to run in the other. Alternatively, to prevent motion duringthe predetermined stages, the transversal beam is cylindrical andpivoted in the outer ends of the arm elements. The wire is guided atleast one turn around the cylindrical transversal beam and the motionprevention means comprises a cotter pin that slides into the cylindricaltransversal beam from the arm element to prevent the rotation of thebeam.

In accordance with another characteristic feature of the invention, thetrailer device includes a second winch, which facilitates loading andunloading of the trailer device especially when it is to be performed byone person. The second winch has a wire adapted to be connected to oneend of the object and which is adapted to pull the object forward whenit is to be placed on the chassis, whereafter the wire of the firstwinch is loosened.

In accordance with another characteristic feature of the invention, thesecond arm of the lever can be lowered against the front end of thetrailer when the arm is not used for lifting in a transportation state.The transportation state refers to the trailer device in a fullycollapsed stage wherein the trailer device is not carrying an object orboat.

To facilitate the raising and lowering of the two arms of the lever,these arms are provided with elastic means which reduce the manual forcerequired to extend the lever.

According to another characteristic feature for the invention, thesecond arm of the lever is formed as part of the frame of the trailer,which in a transportation state is fixed to the chassis of the trailer.

To facilitate the loading and unloading of the trailer the axis ofrotation is placed behind the trailer platform and is verticallypositioned so that the upper part of the axis lies substantially in theplane of the platform.

Furthermore, the lifting device can be connected to a dynamometer, whichdirectly measures the weight of the object.

According to the invention, full security from tilting of the trailerduring loading or unloading and from damages on the towing device forthe towing vehicle as well as on the corresponding coupling device onthe trailer is assured in that the device comprises at least one supportleg, which is mounted at the back of the chassis and can be turned downor turned up. In another embodiment this support leg is detachablymounted.

According to a final characteristic feature of the invention, saiddevice is placed on a boat trailer.

DETAILED DESCRIPTION OF THE DRAWINGS

In the following detailed description the invention will be explainedwith reference to the following drawings wherein:

FIG. 1 is a perspective view of the invention in a fully collapsedstage;

FIG. 2 is a perspective showing of the lever arm at one stage of loadingor unloading with the device according to the invention mounted on aconventional trailer;

FIG. 3 is a perspective view showing the lever arm at a fully extendedstage of loading or unloading;

FIG. 4 shows a first stage of launching of a boat with the deviceaccording to the invention mounted on a boat trailer;

FIG. 5 shows a second stage of launching a boat with the device of thepresent invention; and

FIG. 6 shows a final stage of launching the boat of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 generally shows a conventional trailer with a chassis 1a, wheels1b and a winch 1d whose wire 1e is coupled to an object and which is tobe used for the transfer. The trailer is equipped with coupling means 1fof conventional type to couple the trailer to a motor vehicle with atowing device.

To facilitate the loading and unloading of objects, the traileraccording to the invention is equipped with a device that comprises alever 2, having a first arm 2a and a second arm 2b which can form anangle with respect to each other. Said angle exceeds a right angle andis preferably approximately 100°. The lever 2 is pivoted in an axis 3which is mounted across the back of the chassis. The first arm 2aessentially extends forward from the axis 3 toward said coupling means1f and has a length that differs from the length of the second arm 2b.Both arms are comprised of parallel arm elements 2a1, 2b1; 2a2, 2b2,which are connected to the ends of the rotation axis 3 and linked bytransversal beams 2a3, 2b3 at their outer ends. The distance between thearm elements 2a1, 2b1 and 2a2, 2b2 limits the width of the objects forwhich the device can be used.

In the embodiment which is shown in the drawing, the angle between thearms is determined by a rod 2ab, which is detachably mounted between thearms 2a and 2b. The center of gravity of the trailer can be displaced bya variation of this angle.

The winch 1d is in many cases satisfactory for the handling of an objectwhen loading and unloading a trailer and in particular when launchingand loading a boat, but in the following it will be apparent that it isfavorable to use an additional winch, as is shown in the drawing. Thewire 1e of the winch 1d runs across the transversal beams 2a3, 2b3 atthe outer ends of the lever arms 2a, 2b and has lifting eye bolts 7e2 atthe end.

In accordance with the invention, means to prevent relative motionbetween the lever arm 2b and the wire 1e during predetermined stages oflaunching or loading of a boat are provided for reasons which will beclear from the following.

In the embodiment according to FIG. 1 through FIG. 3, a block 4 isprovided on the upper horizontal beam where the wire 1e runs on thelever arm 2b. The block allows the wire to run in one direction andlocks the wire in the other direction so as to prevent the lever frommoving in relation to the wire when this is not desired. In theembodiment shown in FIG. 4 through FIG. 6, the same function is achievedby a cylindrical and rotatably mounted transversal beam 10b3 mountedbetween arm elements 10b1 and 10b2. The wire 7e1 is guided at least oneturn around the transversal beam 10b3. A cotter pin 10b4 is includedthat can be inserted from the second arm element 10b2 into thecylindrical beam 10b3 to prevent rotation of the beam. The relativemotion must be possible again at a later stage.

To increase the stability at loading or unloading of an object, supportlegs 7c are provided at the back of the trailer, which support legs canbe turned down, turned up, or can be detachably mounted.

The following process of loading a boat onto the trailer will beexplained in detail with reference to FIG. 4 through FIG. 6. Thelaunching is accomplished in an analogous manner, but in a reversedorder.

By means of the towing vehicle, the trailer 7 is parked as close aspossible to the end of the quay or the pier. If the boat is a rowingboat, which is not very heavy, it is unnecessary to turn down thesupport legs 7c. In such a scenario, the towing vehicle 9 functions asthe necessary counterweight.

When handling boats with motors, the support legs should always beturned down to prevent excessive strain on the towing device and thecoupling device. When the arm elements are lowered, i.e. moving freelyaround the axis 11, the telescopically extendable arm elements 10b1,10b2 are pulled out to such a length wherein the boat 8 goes free fromthe side of the quay or the pier when the lifting eye bolts 7e2 areapplied at the center of gravity. In the embodiment shown in thedrawing, the arm elements are manually pulled out and the telescopicalarm elements can be locked in relationship to each other by means of acotter pin. The arm is then raised and the rods 10ab are mounted. It isevident that other known solutions are possible, e.g. motor control,when it is not required for the arm 10b to be turned down.

When the crank of the winch is turned and the wire 7e1 is winched backonto the winch, the boat 8 is lifted out of the water. The wire 7e1 runsacross the transversal beams 10a3, 10b3, and through a mechanicalbalancing, for which the angle between the first 10a and the second 10blever arms is important; the second lever arm 10b is lifted while thefirst lever arm 10a is lowered. The angle is important since iteliminates the need to give the lifting device an initial push to makeit pass the position of balance and thereby make the boat pass over theedge of the quay.

When the first arm 10a and the second arm 10b have about the same angleto the horizontal plane, it is suitable to prevent rotation of thetransversal beam 10b3 by means of the cotter pin 10b4 to lock the wire7e1 in relation to the beam. The mechanical balancing, which resulted inthe lifting of the boat 8, then ceases. It is now also suitable tocouple the wire 12a of the winch 12 to the stem of the boat 8 in orderto control its movements when it is lifted over the boat trailer by thewinching of the wire 7e1. This is accomplished by varying the angle tothe horizontal plane for the arm elements 10b1, 10b2, wherein the angleis increased gradually while the corresponding angle for the lever arm10a is decreased until the arm rests on the chassis 7a. The boat 8 isnow drawn forward by means of the winch 12, while the tension in wire7e1 is released so that the boat finally rests on the roller means 7d.Finally, the rods 7ab are released so that the arm 7b can be turned downand telescoped into the normal position. The loading is now finished andtransportation can take place after the boat 8 has been tied up and thesupport legs 7c have been turned up.

We claim:
 1. A trailer device for use on a trailer having a front andback end including a chassis supported by wheels and a coupling devicelocated at the front of the trailer for connecting the trailer to atowing vehicle, comprising:a lever having a first and second arm, whichsaid first and second arms form an angle with respect to each other andare pivoted about an axis of rotation, said axis of rotation orientedtransversally at the back end the trailer, at which the first arm of thelever points forward from the axis of rotation, the first arm having alength that exceeds a length of the second arm of the lever, the firstand second arms comprised of parallel arm elements with ends, whose endsare connected to an end of the axis of rotation and which at their outerends are linked to respective transversal beams, thereby the lever armsforming a "U" shape, a distance between the outer ends of the first armexceeds a distance between the outer ends of the second arm, saiddistance between ends limiting the width of objects that can be loadedor unloaded from the trailer, the front end of the trailer including awinch tower and a winch, whereby a wire of the winch is adapted to runover the outer ends of the first and second arms, one end of the wireprovided with lifting means for attachment to the object, said first andsecond arms also including means adapted to prevent motion between thefirst and second arms and the wire during predetermined stages of theloading or unloading of the object.
 2. Device in accordance with claim1, characterized in that the transversal beam of the second ever (2b) isprovided with a block (4) through which the wire (1e) runs, which locksthe wire in one direction and allows it to run in another direction orin that the transversal beam (10b3) of the second lever is cylindricaland pivoted in the outer ends (10b1, 10b2) of the arms elements, in thatthe wire (7e1) is guided at least one turn around the cylindrical beam(10b3) and in that said device comprises a cotter that slides in thecylindrical beam (10b3) from the arm element to prevent the rotation ofsaid beam.
 3. Device in accordance with claim 1, characterized in thatit comprises a second winch (5), whose wire is adapted no be connectedto one end of the object and which is adapted to pull the object forwardwhen it is to be placed on the chassis (1a), whereafter the wire (1e) ofthe first recited winch (1d) is loosened.
 4. The trailer device of claim1, wherein the "U"-shaped first arm of the lever for a transportationstate can be turned down against the front end of the trailer, thesecond arm of the lever for a transportation state can be turned downagainst the front end of the trailer and positioned within the "U"-shapeof the first arm of the lever.
 5. Device in accordance with claim 1,characterized in that the arms (2a, 2b) of the lever are provided withelastic means to facilitate the transformation from transportation stateto a lifting state.
 6. The trailer device of claim 1, wherein the lengthof the lever-arms exceeds the length of the trailer and the distancebetween the parallel arm elements of the first and second arms exceedsthe width of the trailer so that the first and second arms do not occupyany loading space in a transportation state.
 7. The trailer device ofclaim 6, wherein the second arm of the lever forms a frame of thetrailer and is fixed to the chassis of the trailer.
 8. The trailerdevice of claim 7, wherein the axis of rotation is placed behind atrailer platform and vertically positioned so that an upper part of theaxis lies substantially in the plane of the platform.
 9. The trailerdevice of claim 8, wherein the lifting means are connected to adynamometer.
 10. The trailer device of claim 1, wherein the trailerdevice comprises at least one support leg, which can be turned down,turned up, or detachably attached to prevent excessive strain on thetowing vehicle or the coupling device.
 11. Device in accordance withclaim 1, characterized in that the device is a boat trailer (10). 12.Device in accordance with claim 1 characterized in that the second arm(10b) is telescopically extendable.
 13. The trailer device of claim 1,wherein the motion prevent means comprises:a block provided on an upperhorizontal beam through which the wire runs, said block locks the wirein a first direction and allows it to run in a second direction oppositeto the first direction.
 14. The trailer device of claim 1, wherein themotion prevent means comprises:the transversal beam having a cylindricalshape and rotatably mounted between the parallel arm elements of thesecond arm; the wire guided at least one turn around the cylindricaltransversal beam; a cotter pin inserted into the second arm and receivedinto the cylindrical transversal beam to prevent rotation of thecylindrical transversal beam.
 15. The trailer device of claim 1, whereinthe motion prevent means in the transportation state can be turned downagainst the front end of the trailer.
 16. The trailer device of claim 1,comprising a means for driving the winch.